Theres a Couple of ways
1.If you are in a network environment than you can install it by using another machines DVD drive
2.Create a image of the Data on the disk
3.Slave/Make youre drive Secondary drive in another machine that has a DVD drive and install OFFICE 07 on youre drive
Anouther alternative is to download the image of the cd you have just recived and use a bit of software you will have to google for as i am not sure of the legality of it and just read the image directly.
With this "bit of software" mount the image as a drive and use your cd key. :)
Easier way would be to get a £12 dvd drive and use that..... At least you have one then and pretty much all media is on dvd's now anyway.